1,1,2-Trichloro-1,2,2-trichloroethane (known in the profession under the name F113) is widely used in industry for the cleaning and degreasing of solid surfaces. Besides its application in electronics to the cleaning of solder fluxes in order to remove the surface-attacking flux which adheres to printed circuits, there may be mentioned its applications to the degreasing of heavy-metal components and to the cleaning of mechanical components of high quality and high precision, such as, for example, gyroscopes and military or aerospace equipment. In its various applications, F113 is most often combined with other organic solvents (for example methanol), preferably in the form of azeotropic or pseudoazeotropic mixtures which do not demix and which, used at reflux, have substantially the same composition in the vapor phase as in the liquid phase.
However, F113 is one of the completely halogenated chlorofluorocarbons which are currently suspected of attacking or damaging stratospheric ozone.
In order to contribute to solving this problem, the present invention proposes to replace the F113-based compositions by a new composition based on methylene chloride and 1,1,1,3,3-pentafluorobutane. The latter compound, known in the profession under the name F365-mfc, has no destructive effect with respect to ozone (ODP=0).